ios - swift xcode : Changing the name/title of a row/cell inside a Table by a text input after pressing a button

Question

向下滚动到第一个类 (MainProjectScene) 的最后一个方法。 “PressedSaveAs”函数就是我要解决的方法，和截图错误的方法是一样的。

当用户按下按钮时，文本输入将出现，当您单击“确定”时，它会将用户输入的文本分配给表格的行/单元格的标题。

错误截图:enter image description here

我想分配给行/单元格标题的文本字段的屏幕截图(这将在我按下按钮时发生，因此功能在 PressedSaveAs 方法中): enter image description here

import UIKit



weak var FirstFileNameTextField: UILabel!



class MainProjectScene: UIViewController

{



    var row: Row?



    override func viewWillAppear(animated: Bool)

    {



        if let r = row

        {



            row!.FileName = r.FileName



            row!.QuartzImage = r.QuartzImage



        }

    }



    override func  viewDidLoad()

    {

        super.viewDidLoad()



        // FacebookButton.addTarget(self, action: "didTapFacebook", forControlEvents: .TouchUpInside)



    }



    @IBOutlet weak var NewFileButton: UIButton!

    @IBOutlet weak var TwoDQuartzButton: UIButton!

    @IBOutlet weak var YouTubeButton: UIButton!

    @IBOutlet weak var TwitterButton: UIButton!

    @IBOutlet weak var OpenFileButton: UIButton!

    @IBOutlet weak var SnapChatButton: UIButton!

    @IBOutlet weak var FacebookButton: UIButton!

    @IBAction func PressedTwoDQuartzButton(sender: UIButton) {



    }



    @IBAction func PressedSnapchatButton(sender: UIButton){



        UIApplication.sharedApplication().openURL(NSURL(string: "https://www.snapchat.com/")!)



    }



    @IBAction func PressedYouTubeButton(sender: UIButton) {



        UIApplication.sharedApplication().openURL(NSURL(string: "https://www.youtube.com/")!)



    }



    @IBOutlet weak var InstagramButton: UIButton!

    @IBAction func PressedFacebookButton(sender: UIButton) {



        UIApplication.sharedApplication().openURL(NSURL(string: "http://www.facebook.com")!)



    }

    @IBAction func PressedInstagramButton(sender: UIButton) {



        UIApplication.sharedApplication().openURL(NSURL(string: "https://www.instagram.com/")!)



    }



    @IBAction func PressedTwitterButton(sender: UIButton) {



        UIApplication.sharedApplication().openURL(NSURL(string: "https://twitter.com/")!)



    }



    @IBOutlet weak var SaveAsButton: UIButton!

    @IBAction func PressedSaveAs(sender: UIButton) //this is the save as function that I would like to know how to change



    {



        //1. Create the alert controller.



        var alert = UIAlertController(title: "Name/rename your file:", message: "Enter a filename to name/rename and save your file", preferredStyle: .Alert)



        //2. Add the text field. You can configure it however you need.



        alert.addTextFieldWithConfigurationHandler({ (textField) -> Void in



            textField.text = "Your file name"

        })



        alert.addAction(UIAlertAction(title: "OK", style: .Default, handler:

            {

                (action) -> Void in

                let textField = alert.textFields![0] as UITextField

                print("Text field: \(textField.text)")

               // rows.cell.textLabel?.text = textField.text

                CurrentFileName = textField.text!

                rows[indexPath.row].FileName = CurrentFileName

        }))



        // 4. Present the alert.

        self.presentViewController(alert, animated: true, completion: nil)





            // rows[indexPath.row].FileName = rows.cell.textLabel?.text



            // rows[i] = textField.text



    }





}

行类

import UIKit





let rows = [

    Row(FileName: "File slot 1",

        QuartzImage: "Image slot 1"),

    Row(FileName: "File slot 2",

        QuartzImage: "Image slot 2"),

    Row(FileName: "File slot 3",

        QuartzImage: "Image slot 3"),

    Row(FileName: "File slot 4",

        QuartzImage: "Image slot 4"),

    Row(FileName: "File slot 5",

        QuartzImage: "Image slot 5"),

    Row(FileName: "File slot 6",

        QuartzImage: "Image slot 6"),

    Row(FileName: "File slot 7",

        QuartzImage: "Image slot 7"),

    Row(FileName: "File slot 8",

        QuartzImage: "Image slot 8"),

    Row(FileName: "File slot 9",

        QuartzImage: "Image slot 9"),

    Row(FileName: "File slot 10",

        QuartzImage: "Image slot 10"),

    Row(FileName: "File slot 11",

        QuartzImage: "Image slot 11"),

    Row(FileName: "File slot 12",

        QuartzImage: "Image slot 12")]



//update contents of the array

//each of the table cell will use the stored information in the array

//



class Row

{

    ///// enum Type: String {

    // }



    var FileName: String

    var QuartzImage: String



    // var type: Type

    // var shortDescription: String

    // var longDescription: String



    init(FileName: String, QuartzImage: String) {

        self.FileName = FileName

        self.QuartzImage = QuartzImage



    }


}

行 TableView Controller 类

import UIKit



var CurrentIndex = 0

var CurrentFileName = ""



class RowTableViewController: UITableViewController {



    override func viewDidLoad() {



        super.viewDidLoad()



        // Uncomment the following line to preserve selection between presentations



        // self.clearsSelectionOnViewWillAppear = false



        // Uncomment the following line to display an Edit button in the navigation bar for this view controller.



        // self.navigationItem.rightBarButtonItem = self.editButtonItem()



    }



    override func didReceiveMemoryWarning() {



        super.didReceiveMemoryWarning()



        // Dispose of any resources that can be recreated.



    }



    // MARK: - Table view data source



    override func numberOfSectionsInTableView(tableView: UITableView) -> Int {



        // #warning Incomplete implementation, return the number of sections



        return 1



    }



    override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {



        // #warning Incomplete implementation, return the number of rows



        return rows.count



    }



    override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {



        let cell = tableView.dequeueReusableCellWithIdentifier("FileSlot", forIndexPath: indexPath)



        let filename = rows[indexPath.row].FileName



        print(filename)



        cell.textLabel?.text = filename



        return cell



    }

    override func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath)

    {



        let title = "List of Files"

        let message = "You have selected \(rows[indexPath.row].FileName)"



        // CurrentIndex = rows[didSelectRowAtIndexPath.row]

        var i = 0

        CurrentIndex = indexPath.row

        CurrentFileName = rows[indexPath.row].FileName

        let alertController = UIAlertController(title: title, message: message, preferredStyle: .Alert)

        let okayAction = UIAlertAction(title: "Okay", style: .Default, handler: nil)

        alertController.addAction(okayAction)

        presentViewController(alertController, animated: true, completion: nil)

        self.tableView.deselectRowAtIndexPath(indexPath, animated: true)



    }

override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {



        // Get the new view controller using [segue destinationViewController].



        // Pass the selected object to the new view controller.



        if let detailViewController = segue.destinationViewController as? MainProjectScene {



            if let cell = sender as? UITableViewCell {



                if let indexPath = self.tableView.indexPathForCell(cell) {



                    detailViewController.row = rows[indexPath.row]



                }



            }



        }



        //   let index = RowTableViewController.indexPathForSelectedRow()



        //let currentCell = RowTableViewController.cellForRowAtIndexPath(RowTableViewController.indexPath) as UITableViewCell



        //println(currentCell.textLabel!.text)



    }



    /*



    // Override to support conditional editing of the table view.



    override func tableView(tableView: UITableView, canEditRowAtIndexPath indexPath: NSIndexPath) -> Bool {



    // Return false if you do not want the specified item to be editable.



    return true



    }



    */



    /*



    // Override to support editing the table view.



    override func tableView(tableView: UITableView, commitEditingStyle editingStyle: UITableViewCellEditingStyle, forRowAtIndexPath indexPath: NSIndexPath) {



    if editingStyle == .Delete {



    // Delete the row from the data source



    tableView.deleteRowsAtIndexPaths([indexPath], withRowAnimation: .Fade)



    } else if editingStyle == .Insert {



    // Create a new instance of the appropriate class, insert it into the array, and add a new row to the table view



    }



    }



    */



    /*



    // Override to support rearranging the table view.



    override func tableView(tableView: UITableView, moveRowAtIndexPath fromIndexPath: NSIndexPath, toIndexPath: NSIndexPath) {



    }



    */



    /*



    // Override to support conditional rearranging of the table view.



    override func tableView(tableView: UITableView, canMoveRowAtIndexPath indexPath: NSIndexPath) -> Bool {



    // Return false if you do not want the item to be re-orderable.



    return true

    }


}

Answer 1

我认为 indexPath 的范围是问题所在，您需要使用

weakSelf.indexPath (if a class level variable)

这是因为您使用的闭包(或 block )与方法中的其余代码具有不同的作用域。您需要使用 weakSelf 而不是简单的“self”的原因。是为了避免保留循环，可以找到对此进行解释的文档 here